Gamma-carbolines possessing central nervous system activity are known. Representative of the compounds found in the literature are those disclosed by Plattner et al., U.S. Pat. No. 4,001,263 and Welch, U.S. Pat. No. 4,224,329 as 2-substituted-5-aryl-tetra-and hexahydro-pyrido[4,3-b]indoles. Each reference discloses preferred phenyl(oxy or oxo)alkyl substitution in 2-position.